Ultrasound Device for Probe Guidance and Sterilizable Shield for Same

ABSTRACT

Disclosed are medical probe devices and methods for use guiding of percutaneous probes during medical procedures. The probe devices include an ultrasound transducer housing having a passage therethrough configured to accommodate a probe. The devices can be utilized to guide a probe through the probe guide to a percutaneous target with real time visualization of the probe during the procedure. In addition, the devices can include a sterilizable shield including a sterile probe guide such that the transducer housing itself can be separated from a subject by a sterile barrier. The sterilizable shield can be a single-use shield that can prevent contamination and re-use of the shield. The devices can define a beneficial geometry conducive to use by a single operator that can be utilized for percutaneous targets near the skin surface and can enable excellent contact between the device and the skin surface of a subject.

CROSS REFERENCE TO RELATED APPLICATION

This application is a divisional application of and claims filingpriority to U.S. patent application Ser. No. 12/576,487 having a filingdate of Oct. 9, 2009, which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

Medical probe devices are utilized for many purposes, chief of whichinclude catheterization, centesis, and biopsy procedures. Percutaneousplacement of probes using these devices is often performed withtechniques which rely on ascertaining the correct locations of palpableor visible structures. This is neither a simple nor a risk-freeprocedure. For instance, proper insertion and placement of apercutaneous probe depends on correct localization of anatomicallandmarks, proper positioning of the patient in relation to the careprovider, and awareness of both the target's depth and angle from thepoint of probe insertion. Risks of unsuccessful placement of a probe canrange from minor complications, such as patient anxiety and discomfortdue to repetition of the procedure following incorrect initialplacement, to severe complications, such as pneumothorax, arterial orvenous laceration, or delay of delivery of life-saving fluids ormedications in an emergency situation.

Ultrasound guided techniques and devices have been developed to aid incorrect placement of percutaneous probes. Ultrasound guided techniquesoften utilize two people, an ultrasound operator who locates theinternal target and keeps an image of the target centrally located on amonitor, and a care provider who attempts to guide the probe to thetarget based upon the sonogram. Such techniques are very difficultperceptually. For instance, these techniques are complicated by the factthat the person targeting the tissue with the probe is not the sameperson as is operating the ultrasound. In addition, the generally thin,cylindrical probe is usually small and reflects very little of theultrasound beam. Moreover, as the cylindrical probe and the ultrasoundbeam are not generally normal to one another, the small amount ofultrasonic energy that is reflected from the probe will reflect at anangle to the incident beam, resulting in little if any of the reflectedenergy being detected by the ultrasound transducer. As a result, theprobe itself is difficult to visualize in the sonogram and the personplacing the probe must attempt to guide the probe to the correctlocation using minimal visual feedback. For example, the only visualfeedback available is often only subtle artifacts of the motion of theprobe such as slight changes in the sonogram as the probe deflects andpenetrates the surrounding tissue. The trained observer can pick upsubtle ultrasonic shadow artifacts deep to the probe created when theprobe blocks the transmission of the ultrasound beam to the tissuebelow, and such subtle artifacts can be used to help guide the probe tothe targeted location.

In an attempt to relieve the difficulties of ultrasound guided probetechniques, systems have been developed including a probe guide whichcan be attached to an ultrasound transducer housing. Problems stillexist with such devices however. For instance, the probe guide is to oneside of the ultrasound transducer housing in these devices, and theprobe is often inserted at a fixed angle to the scanned plane displayedon the sonogram, restricting the intersection of the scanned plane andthe point of the probe to a very small area in space. In addition, andas with hand-guided ultrasound techniques, very little, if any,ultrasonic energy is reflected from the probe back to the transducer. Infact, due to the lack of lateral motion of the probe, visual cues to thelocation of the probe tip may be even more difficult to discern on asonogram when using these devices. In addition, in many of thesedevices, the probe passes through the ultrasound beam at a fixed depthrange depending on the set angle of the probe guide, and this may notcorrespond to the depth of the target, in which case it may not bepossible to show the juncture of the target and the probe tip on thesonogram at all.

What are needed in the art are improved ultrasound devices and methodsfor using such devices. For instance, what are needed in the art areultrasound probe devices that can be utilized by a single operator toaccurately visualize the delivery of a probe to a percutaneous target.

SUMMARY OF THE INVENTION

Disclosed in one embodiment is a medical probe device. The skincontacting surface can include a first portion and a second portion thatare angled with respect to one another. More specifically, the firstportion can define a first plane and the second portion can define asecond plane, and these two planes can intersect one another to definean angle therebetween that is greater than about 150° and less than180°. In addition, the first portion of the skin contacting surface candefine a probe guide therethrough, and the second portion can beassociated with an ultrasound transducer such that an ultrasonic beamtransmitted from the ultrasound transducer issues from the secondportion. In one embodiment, the first portion of the skin contactingsurface can be defined by a first portion of the medical probe deviceand the second portion of the skin contacting surface can be defined bya second portion of the medical probe device, and the first and secondportions of the medical probe device can be removably cooperable withone another.

The probe device can be an ultrasound transducer housing, or, in anotherembodiment, can include a sterilizable shield that can enclose anultrasound transducer housing.

A probe device as disclosed herein can also include a clamp for clampinga probe in the probe guide of the device, for instance after the probetip has reached a targeted percutaneous target.

Disclosed devices can be connectable to a monitor for displaying asonogram. Moreover, the path of a probe guided through the probe guidecan define a line that is coincident (i.e., within) the scanned plane ofa sonogram formed by the ultrasound device.

A device can include a detector for detecting motion of a probe withinthe probe guide. Information from the detector can be processed and, inone embodiment, can be displayed as an image of a virtual probe on themonitor overlaying the sonogram, providing a real-time visualization ofthe location of the probe tip during a procedure.

A probe device can include additional beneficial features. For example,in one embodiment, a skin contacting surface of a probe device caninclude at least one raised ridge on the surface that can improvecoupling between the skin and the probe device, generally in conjunctionwith ultrasonic gel between the two. In another embodiment, a skincontacting surface can include a wedge formed of an ultrasonictransmissive material to improve coupling between the skin and the probedevice and/or to improve visualization of percutaneous targets that areclose to the surface of the skin.

Also disclosed herein is a single-use sterilizable shield as can beutilized with an ultrasound transducer. In one embodiment, asterilizable shield can include a first section, a second section and afastener for connecting the first section and the second section to oneanother. Beneficially, the fastener can be a single-use fastener thatcan be permanently disabled upon disconnection and separation of thefirst section and the second section from one another that can preventreuse of a shield and enhance patient safety.

Also disclosed is a multi-piece device including multiple removablyattachable portions. For instance, a device can include a first portionthat incorporates an ultrasound transducer and a second portion thatdefines all or a portion of a probe guide, and the two portions can beremovably attached to one another. A device can also include a detectorfor detecting the presence or the motion of a probe within the probeguide.

Also disclosed are methods for guiding a probe to a percutaneous target.Methods can include, for example, utilizing a probe guide including anultrasound device with a single-use sterilizable shield and disablingthe shield upon disassembly of the device. Beneficially, disclosedmethods can be carried out by a single operator during a medicalprocedure.

BRIEF DESCRIPTION OF THE FIGURES

A full and enabling disclosure of the present subject matter, includingthe best mode thereof to one of ordinary skill in the art, is set forthmore particularly in the remainder of the specification, includingreference to the accompanying figures in which:

FIG. 1A illustrates one embodiment of an ultrasound device as disclosedherein;

FIG. 1B illustrates a side view of the base of the device of FIG. 1A;

FIG. 1C illustrates a side view of the base of another embodiment of anultrasound device as disclosed herein;

FIG. 2 illustrates a bottom view of the device of FIG. 1;

FIG. 3 illustrates one embodiment of a multi-section sterilizable shieldas disclosed herein;

FIG. 4 illustrates the lower section of the sterilizable shieldillustrated in FIG. 3;

FIG. 5A illustrates a bottom view of the lower section of thesterilizable shield illustrated in FIG. 3;

FIG. 5B illustrates a partial bottom view of another embodiment of asterilizable shield as disclosed herein;

FIG. 6 illustrates the upper section of the sterilizable shieldillustrated in FIG. 3;

FIGS. 7A and 7B illustrate two views of the clamping mechanism of thesterilizable shield of FIG. 3; and

FIG. 8 illustrates one embodiment of a method for utilizing a device asdisclosed herein.

FIG. 9 illustrates an ultrasound transducer housing that can beremovably attachable to a portion of a probe device defining a probeguide;

FIG. 10A and 10B illustrate a probe device including the ultrasoundtransducer housing of FIG. 9 enclosed in a sterilizable shield portion,a separable portion removably attachable thereto that defines a probeguide, and a clamp removably attachable thereto, with FIG. 10A showingthe sections removed from one another and FIG. 10B showing the sectionswhen attached together.

FIG. 11 illustrates another embodiment of a probe device as disclosedherein.

FIG. 12 is a side view of the probe device illustrated in FIG. 11.

FIG. 13 is a front view of the probe device illustrated in FIG. 11.

FIG. 14 illustrates the device of FIG. 11 including a removablyattachable probe guide portion.

FIG. 15 is a side view of the device of FIG. 14.

FIG. 16 is a front view of the device of FIG. 14.

FIG. 17 illustrates the device of FIG. 14 with a clamp removablyattached to the probe guide portion.

FIG. 18 is a side view of the device of FIG. 17.

FIG. 19 is a front view of the device of FIG. 17.

Repeat use of reference characters in the present specification anddrawings is intended to represent the same or analogous features ofelements of the disclosed subject matter. Other objects, features andaspects of the subject matter are disclosed in or are obvious from thefollowing detailed description.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Reference will now be made in detail to various embodiments of thedisclosed subject matter, one or more examples of which are set forthbelow. Each embodiment is provided by way of explanation of the subjectmatter, not limitation of the subject matter. In fact, it will beapparent to those skilled in the art that various modifications andvariations may be made in the present disclosure without departing fromthe scope or spirit of the subject matter. For instance, featuresillustrated or described as part of one embodiment, may be used inanother embodiment to yield a still further embodiment. Thus, it isintended that the present disclosure cover such modifications andvariations as come within the scope of the appended claims and theirequivalents.

Definitions

As utilized herein, the term “probe” generally refers to a device thatcan be guided to a percutaneous location, for instance for delivery of atherapeutic, e.g., a compound or a treatment, to the location; forremoval of material from the location; and so forth. For example, theterm “probe” can refer to a needle, a tube, a biopsy device, or anyother item that can be guided to a percutaneous location. In general, aprobe can be guided by and used in conjunction with an ultrasound deviceas described herein.

As utilized herein, the term “probe device” generally refers to a devicethat can be utilized in conjunction with a probe, but does notnecessarily include the probe itself.

DETAILED DESCRIPTION

According to one embodiment, disclosed herein are devices and methodsfor use in guiding a percutaneous probe during a medical procedure. Inone preferred embodiment, disclosed herein are probe devices that caninclude an ultrasound transducer therein. Devices can define an openingto accommodate a probe therethrough so as to improve coordinationbetween a sonogram formed by the ultrasound device and the path of aprobe passing through the opening. In one embodiment, disclosed devicescan include a visualization system so as to provide a real-time image ofa virtual probe on a sonogram and improve delivery of a probe to apercutaneous target.

Also disclosed herein are sterilizable shields that can surround all ora portion of an ultrasound transducer to form a sterilizable probedevice. Thus, disclosed probe devices can be utilized in an ultrasoundguided medical procedure that requires a sterile field to ensure thesafety of a patient. For instance, disclosed devices can be used in acentral venous catheterization procedure, in a biopsy procedure, and thelike.

Beneficially, disclosed devices can be formed so as to conveniently beutilized by a single operator who can control an ultrasound transducerand also deliver a probe using the probe guidance system. Discloseddevices can include a variety of other beneficial features as well. Forexample, features of disclosed devices can improve contact and gelcoupling between a skin surface and the surface of a device, can improvethe effective field of the sonogram formed with the ultrasoundtransducer, and can prevent non-sterile use of a sterilizable shield ofa device, all of which are described in greater detail herein.

In one preferred embodiment, disclosed devices can incorporate a systemthat can be used to visualize a percutaneous probe as it is being guidedwith a device. One preferred embodiment of a visualization system as maybe incorporated with disclosed devices has been described in U.S. Pat.No. 7,244,234 to Ridley, et al., which is incorporated herein byreference. Through utilization of a visualization system, the path of aprobe guided with a device and hence the location of the probe tip canbe more clearly known in relation to a target imaged by the ultrasounddevice.

In accord with the present disclosure, FIG. 1A illustrates oneembodiment of an ultrasound transducer housing generally 100. Transducerhousing 100 includes handle 102, post 104, and base 106. FIG. 2 providesa bottom view of the transducer housing 100. An ultrasound transducer120 that transmits and receives ultrasonic waves can be located in base106, as shown. Ultrasound transducer housing 100 can be formed of anysuitable materials. For instance, any moldable polymeric material thatcan securely encase the ultrasound transducer 120 as well as containassociated electronics, wiring, switches, and the like and will notinterfere with the functioning of the transducer 120 can be utilized,

Any type of ultrasound transducer as is generally known in the art canbe incorporated in transducer housing 100. By way of example, apiezoelectric transducer formed of one or more piezoelectric crystallinematerials arranged in a two or three-dimensional array can be utilized.Such materials generally include ferroelectric piezoceramic crystallinematerials such as lead zirconate titanate (PZT). In one embodiment, theelements that form the array can be individual electrode or electrodesegments mounted on a single piezoelectric substrate, such as thosedescribed in U.S. Pat. No. 5,291,090 to Dias, which is incorporatedherein by reference thereto.

In general, an ultrasound transducer 120 can be formed of multipleelements; however, single crystal devices are also encompassed by thepresent disclosure. The use of a multiple element ultrasound transducercan be advantageous in certain embodiments, as the individual elementsthat make up the array can be controlled so as to limit or prevent anybreak or edge effects in the sonogram. For instance, the firing sequenceof individual crystals can be manipulated through various controlsystems and prevent any possible ‘blind spots’ in the sonogram as wellas to clarify the edges of individual biological structures in thesonogram. Such control systems are generally known in the art and thuswill not be described in detail.

Referring again to FIG. 1A, ultrasound transducer housing 100 defines aprobe guide opening 126 that passes through base 106. As can be seen inFIG. 2, probe guide opening 126 can be aligned with transducer 120. Aprobe that is guided through the probe guide opening 126 can travel on apath that is generally parallel to the scanned plane of a sonogramformed by use of the ultrasound device. In general, the scanned plane(i.e., the plane of the sonogram) is the geometric central plane of thebeam transmitted from the ultrasound transducer 120. In one preferredembodiment, the path of a probe guided through probe guide opening 126can be within the scanned plane. This is not a requirement of thepresent disclosure, however. For instance, the path of a probe passingthrough probe guide opening 126 can be at an angle to the scanned planesuch that it intersects the scanned plane at a point. By way of example,the line defined by the path of a probe passing through the probe guideopening 126 can be at an angle of ×1° of the scanned plane, or at agreater angle, in another embodiment. For instance, a line defined bythe path of a probe passing through the probe guide opening 126 can beat an angle of ±10, ° ±20°,±45°, or even greater, in other embodiments.

Generally, ultrasound transducer 120 can be connected via signal wiresin a cable 124 that leads to a processor that processes the data to forma sonogram on a monitor, as is generally known in the art. In theparticular embodiment as illustrated in FIG. 1A, cable 124 is internalto handle 102 of the ultrasound transducer housing 100, though thisparticular arrangement is not a requirement of the disclosure. Handle102 can generally be set at an angle to post 104 of transducer housing100 so as to be comfortably held in the hand while the device is beingutilized. For instance, in the illustrated embodiment, handle 102 isabout 90° to post 104, though this angle can be varied as desired.Moreover, in another embodiment described further herein, a device neednot include an extending handle portion at all.

Referring to FIG. 1B, base 106 defines a lower surface 108 definingprobe guide opening 126 and lower surface 110 from which an ultrasonicbeam emitted by transducer 120 can issue. Surfaces 108 and 110 togethercan form a skin contacting surface on the base 106 of the device 100. Ascan be seen, surfaces 108 and 110 are contiguous and angled with respectto one another. The angle between surface 108 and 110 can vary. Forinstance, in one embodiment the angle marked as θ in FIG. 1B can varyfrom 0 to about 30° or from about 10° to about 20° in anotherembodiment. Accordingly, the angle between surfaces 108 and 110 can begreater than about 150° and less than 180° in one embodiment, or greaterthan about 160° and less than about 170° in another embodiment.

It has been found that such geometry can be beneficial in certainembodiments. For instance, referring to FIG. 1B, base 106 is illustratedwith the edges of a scanned plane formed by ultrasound transducer 120shown within broken lines 4 and 6. The distance 8 from the terminationof probe guide opening 126 to the edge 4 of the scanned plane is alsoshown. During use, the portion of base 106 including surface 110 canpress into the skin of a subject somewhat and ensure good contactbetween the ultrasound transducer 120, ultrasonic gel, and the skin.Upon passing a probe through the probe guide opening 26, the probe willcontact the skin and travel the short percutaneous distance 8 beforeentering the ultrasound beam. The distance 8 can depend upon the anglebetween the surfaces 108 and 110, but can be relatively small. Forinstance, distance 8 can be less than about 25 mm, less than about 10mm, less than about 5 mm or less than about 1 mm.

In comparison, FIG. 1C illustrates a base 205 in which the entire bottomedge of base 205 is planar, i.e., the skin contacting surface of base205 does not include angled portions. FIG. 1C also illustrates the edgesof a scanned plane formed by transducer 120 by use of broken lines 204and 206. As can be seen, the distance 208 between the point a probe willexit probe guide opening 226 and enter the scanned plane at 204 isgreater than the distance 8 in the embodiment in FIG. 1B. An embodimentincluding a base that defines an angled bottom surface, as isillustrated in FIG. 1B may be preferred in those embodiments in which apercutaneous target may be close to the skin surface.

It should also be understood that while the skin contacting surface andportions thereof of the illustrated probe devices are generally planar,this is not a requirement of the disclosed subject matter. For instance,with regard to FIG. 1B, surface 108 and/or surface 110 can be curved,e.g., can define an arcuate profile along either or both of the axes ofthe surface. In this embodiment, a curved surface can define a planebetween the intersection line of two portions (e.g., surface 108 andsurface 110) forming the skin contacting surface and a point at theouter edge of the curved surface. Planes defined by a curved skincontacting surface can correspond in a like manner to a planar skincontacting surface (or portions thereof) as described above.

In another embodiment, the skin contacting surface of a device can beassociated with a removably cooperable material so as to encourageimproved imaging of a percutaneous location. For instance, a planar skincontacting surface, such as is illustrated in FIG. 1C, or a portion ofan angled skin contacting surface, such as surface 108 of FIG. 1B, canbe associated with an ultrasound transmissive wedge formed of anultrasonic transmissive material so as to alter the relative orientationbetween the skin surface and an ultrasound device. For instance apliable saline-filled container can be held against or attached to thebase of surface 108 to alter the relative orientation of the surfaces.Such a device can be utilized to, e.g., more clearly visualizepercutaneous targets that are close to the skin surface. An ultrasoundtransmissive wedge can be located on the skin contacting surface of adevice utilizing a small amount of ultrasonic gel for a temporaryattachment, or utilizing a biocompatible adhesive for a more permanentattachment, or by any other suitable adherence method.

It should be understood that any particular geometric configuration fortransducer housing 100 and its individual sections is not essential tothe present invention. For example, the base 106 of transducer housing100 may be oblong, square, round, rectangular or any other suitableshape. In certain embodiments, the shape of ultrasound housing 100 maybe particularly designed to fit specific locations of the anatomy. Forexample, ultrasound housing 100 may be shaped to be utilizedspecifically for infraclavicular approach to the subclavian vein,approach to the internal jugular vein, specific biopsy proceduresincluding, without limitation, breast biopsy, thyroid nodule biopsy,prostate biopsy, lymph node biopsy, and so forth, or some other specificuse. Variations in shape for any particular application can include, forexample, a specific geometry for the footprint of base 106, alterationin the size of post 104 and/or handle 102, as well as variation inangles at which various elements of a device meet each other, such asthe angle defined by the bottom of base 106 previously discussed. Forexample, the footprint of base 106 can be any suitable shape and size,e.g., rectangular, round, oblong, triangular, etc. By way of example,the skin contacting surface of base 106 can be between about 0.5 inchesand about 6 inches on its greatest length. In one embodiment, thefootprint of base 106 can be about 0.5 inches on its greatest width soas to promote stability of the device during use. In other embodiments,it can be larger, however, such as about 1 inch on its greatest width,about 2 inches on its greatest width, or even larger.

Transducer housing 100 can be used as is, with no additional shield orcovering over the housing 100. According to this embodiment, a probe,e.g., a needle, can pass through probe guide opening 126 and can bedirected to a target that is visualized on a sonogram formed by use ofultrasound transducer 120. According to another embodiment, however, allor a portion of transducer housing 100 can be encased in a sterilizableshield, for instance in those embodiments in which a probe is intendedfor use in a sterile field. According to this embodiment, a transducerhousing can be encased in a sterilizable shield that can provide asterile barrier between a patient and the ultrasound transducer housing100 during a medical procedure.

A sterilizable shield can generally be formed of a number of differentsterilizable, biocompatible materials. For instance, a sterilizableshield can be formed of relatively inexpensive single-use materials thatcan be sterilized as are generally known in the art such that the entireshield can be properly disposed of following use. In another embodiment,a sterilizable shield can be utilized multiple times, in which case itcan be formed of a material that can be properly sterilized betweenuses. By way of example, a sterilizable shield can be formed of amoldable or extrudable thermoplastic or thermoset polymeric materialincluding, without limitation, polyethylene, polypropylene,polymethylpentene (TPX), polyester, polyvinyl chloride, polycarbonate,polystyrene, and so forth.

FIG. 3 illustrates one example of a sterilizable shield 130 as may beutilized to encase ultrasound transducer housing 100. Sterilizableshield 130 can include a lower section 132, details of variousembodiments of which are shown in FIG. 4 and FIG. 5, and an uppersection 134, details of which are shown in FIG. 6.

With reference to FIG. 4, shield section 132 can include a base 136formed of an ultrasonic transmissive material. Base 136 can be of anysuitable size and shape, but formed such that ultrasound transducerhousing base 106 may be seated firmly in shield base 136. Generally, asmall amount of an ultrasonic gel can be placed between the bottomsurface of transducer housing base 106 and shield base 136 duringseating to prevent any air between the two and promote transmission ofultrasonic waves.

Arising out of shield base 136 is guide post 138. Guide post 138 definesat least a portion of a probe guide 139 therethrough. Probe guide 139extends uninterrupted completely through both guide post 138 and shieldbase 136. Guide post 138 can include tabs as shown, or other formationssuch as hooks, insets, or the like that can be utilized to properlyassemble shield base 136 about ultrasound transducer housing 100. In oneembodiment, guide post 138 may include a removable cap (not shown) forprotection of the interior sterile surface of probe guide 139 duringassembly of shield 130 with ultrasound transducer housing 100.

As can be seen, shield section 132 can also include tabs 140, 142, 144,etc. that can be utilized in properly seating ultrasound housing 100within shield 130 as well as aligning shield section 132 with shieldsection 134 when assembling the complete shield 130 about an ultrasoundtransducer housing 100.

In the illustrated embodiment, tabs 140 on shield section 132 matchcorresponding notch 141 on shield section 134 shown in FIG. 6, Togethertabs 140 and notch 141 form a fastener that can secure shield section132 and shield section 134 to one another. During assembly, tabs 140 cansnap into notch 141 to securely fasten the two sections together andprevent separation of the sections 132, 134 during use. Of course, ashield can include additional fasteners at other locations between thetwo sections, or can include a single fastener at an alternativelocation, as would be known to one of skill in the art.

In order to disassemble shield 130, tabs 140 can be simply pinchedtogether and slid out of notch 141. In another embodiment, a single-usefastening mechanism can be employed to secure sections of a sterilizableshield to one another. According to this embodiment, in order todisassemble a shield following use, the tabs of the fastener can bepermanently disabled. For instance, tabs 140 and/or notch 141 can bepermanently broken away from the shield by a pulling or twisting motion,allowing the shield sections to come apart and also ensuring that theshield, which is no longer sterile, cannot be utilized again. Any methodthat can ensure that a fastener can only be utilized a single time mayalternatively be utilized.

Referring to FIG. 5A, the bottom of shield section 132 can be seen. Thebottom surface of base 136 of section 132 includes a series of ridges150 running along a portion of base 136. It has been found thatinclusion of such ridges on the skin-contacting surface of a device canprovide benefits to disclosed devices and methods. For instance, theinclusion of ridges on the skin contacting surface can push and betterhold ultrasonic gel between the device and the skin surface, preventingformation of an air gap between the two and improving coupling between asubject's skin and the device. In addition, ridges along the skincontacting surface can also add an extra pushing force against the skinitself, better holding the skin tightly against the base of thetransducer, and further improving contact between the device and asubject's skin, thereby further improving coupling between the subjectand the device and providing an optimal ultrasound image.

Though illustrated as two ridges running along the length of the shieldbase, this particular arrangement is not required for the ridges. Forinstance, FIG. 5B illustrates another embodiment, including a pluralityof ridges 150 running across the width of the bottom surface of a base236 of a sterilizable shield. Moreover, in those embodiments in which anultrasound transducer housing is intended for use without a sterileshield, either in a non-sterile field or in those embodiments in whichthe ultrasound device itself is sterilizable, ridges can be included onthe skin contacting surface of the ultrasound transducer housing itself.

Ridges formed on the skin contacting surface of a device can cover theentire skin contacting surface, or only a part of the surface, asdesired. For instance, the ridges can cover at least a portion of theskin contacting surface through which an ultrasonic beam is transmitted,or can also cover other portions of the skin contacting surface, and inparticular, that portion in the vicinity of the probe guide (e.g., oneither or both surfaces 108 and 110 of FIG. 1A). Ridges can be ofparticular benefit on a planar skin contacting surface, such as thatillustrated in FIG. 1B, so as to encourage good contact and couplingbetween a subject's skin, ultrasound coupling gel, and the skincontacting surface of the device,

Ridges 150 can be formed to any size and shape and of any suitablebiocompatible material that can also be, in certain embodiments, asterilizable material. For example, ridges can have a rounded orstraight edge, an individual ridge can lie in a straight line across askin contacting surface or can curve across the surface, they can varyin height as measured from the base surface to the top edge of theridge, multiple ridges on a single device can be identical to oneanother or can vary, ridges can be continuous over a surface ordiscontinuous, and so forth.

In one embodiment, ridges 150 can be formed of the same material asother portions of a shield or transducer housing. For instance, theentire section 132, including ridges 150 can be injection molded from asingle polymeric material. In another embodiment, different portions ofa sterilizable shield can be formed of different materials. Forinstance, ridges 150 can be formed of a polymeric material that issofter than is used to form the remainder of sterilizable shield. By wayof example, a relatively soft elastomeric polymer (e.g., rubber,styrene-butadiene, soft polyurethanes, etc.) can be utilized. In suchcases, ridges can be attached to a device following formation, forinstance utilizing a biocompatible adhesive as is known in the art. Inone embodiment, ridges can be formed on a specifically shaped componentto be attached to the base of the device. For instance, a series ofridges can be formed on an ultrasound wedge as previously discussed,that can be attached either temporarily or permanently to the base of adevice.

As previously stated, the sterilizable shield need not cover the entireultrasound transducer house. For example, in one embodiment, asterilizable shield can cover just that portion of an ultrasoundtransducer housing from which an ultrasonic beam can be emitted. Forinstance, a shield defining one or more ridges thereon can simply snaponto the base of an ultrasound transducer housing, covering that portionof the housing that will contact a user's skin.

Another beneficial feature of disclosed devices can be the geometry of ahandle of a device. For instance, as previously mentioned with regard tothe transducer housing, the angle at which a handle is placed on a probedevice can be varied so as to obtain a more comfortable grip on thedevice while holding the transducer base tightly against the skin.Additional aspects of a can be improved as well. For example, as can beseen on FIG. 5A the handle of shield section 132 can include a fingergrip 152 that can improve the grip of a user on the device. In otherembodiments additional finger grips can be included, as desired. Forinstance, in one embodiment finger grips can be provided on a handlesuch that the handle is specifically designed for left-handed orright-handed use.

Sterilizable shield 130 also includes section 134, illustrated in FIG.6. Section 134 can be removably attached to section 132 to enclose anultrasound transducer housing 100, as previously discussed. Section 134defines the terminal portion 151 of probe guide 139 in portion 160.Terminal portion 151 is sized so as to snugly reside over the top ofguide post 138 of section 132 and form uninterrupted probe guide 139extending from the top surface of portion 160 of section 134 to thebottom surface of base 136 of section 132.

It should be understood that a sterilizable shield as disclosed hereinis not limited to two completely separable portions. For instance, asterilizable shield can be hinged and/or can include additionalportions, as desired. For instance, a sterilizable shield can be formedof two, three, or more separable sections that can be assembled toenclose all or a portion of an ultrasound housing and form a sterilebarrier between the enclosed housing and an exterior field. In anotherembodiment, a sterilizable shield can be of a unitary construction. Forinstance, a sterilizable shield can be of a pliant material that canenclose all or a portion of an ultrasound housing and form a sterilebarrier between the enclosed housing and an exterior field.

To assemble a shielded device, ultrasound transducer housing 100defining probe guide opening 126 can be seated in shield base 136 ofsection 132 such that guide post 138 extends through transducer housingprobe guide opening 126. As probe guide opening 126 of transducerhousing 100 is slid over guide post 138, tabs on guide post 138 canslide or snap into recesses of probe guide opening 126 (not shown),helping to properly seat transducer housing 100 in section 132. Afterultrasound transducer housing 100 is seated in section 132, section 134can be aligned with section 132 and fastened into place to cover the topof transducer housing 100. If a protective cap covers the end of guidepost 138, it can be removed during assembly and maintain the sterilityof the interior of the probe guide 139 throughout the assembly process.Tabs 140 can snap or slide into recesses notch 141 to fasten and securesection 132 and 134 together.

Following the above described assembly process, probe guide 139 canextend continuously from the top of portion 160 of shield portion 134through the shield base 136. Moreover, and of great benefit to thedevice, probe guide 139 can be sterile and within the probe guideopening 126 of ultrasound transducer housing 100.

Many procedures require a probe to remain at the subcutaneous target fora period of time following insertion of a probe. For example, during theSeldinger technique common for central venous catheter placement, acannulated needle attached to a syringe is first guided into a vein.After the needle tip is in the lumen of the vein, the needle is held inplace while a guide wire is fed down through the needle and into thevein. During this process, only a slight movement of the needle cancause the needle tip to move out of the vein, and the entire proceduremust be repeated.

In order to prevent excessive motion of a probe tip following insertionto a target, one embodiment includes a clamp for the probe. In thisembodiment, a device can include a clamp that can firmly hold a probe inthe probe device and prevent motion of the probe during subsequentprocedures such as catheter insertion, biopsy procedures, fluidaspiration, or the like. Motion of the percutaneous probe tip can bemuch less likely when the probe is securely clamped to the probe deviceand the probe device is in turn held and stabilized by pressing againstthe subject's skin surface as compared to when only the probe itself isheld without clamping to the larger probe device.

One embodiment of a clamp for use with disclosed probe devices can beseen in FIG. 3. As can be seen, a probe 154 can extend through the probeguide of sterilizable shield 130. Clamp 156 sits atop shield section 134such that probe 154 passes through clamp aperture 158 as shown.

Additional details of clamp 156 can be seen with reference to FIGS. 7Aand 7B. Aperture 158 includes a wide portion and a narrow portion anddefines a clamping surface. The wide portion can be of a size such thata probe can pass freely through the wide portion without hindrance.Aperture 158 can gradually narrow from the wide portion of the apertureto form the narrow portion extending to a tip. Thus, when a probe islocated in the wide portion of aperture 158, the clamp can be slid,rotated, or otherwise moved in relation to the probe such that theclamping portion of the clamp crosses the axis of the probe and aclamping surface of the clamp, e.g., a surface of aperture 158 at thenarrow portion, can contact the probe and the probe can become tightlytrapped in the narrow portion of the aperture 158 as the width of thenarrow portion of aperture 158 decreases.

In another embodiment, rather than trapping a probe between two opposingclamping surfaces, as is the case for the clamp of FIGS. 7A and 7B, aclamping surface can force a probe against the wall of the probe guideto secure the probe in place. For example a clamping surface can be seton a clamp and at an angle with reference to the probe guide. Thus, asthe clamp is moved and crosses the probe guide axis, the probe held inthe probe guide contacts the clamping surface and becomes pressedagainst the wall of the probe guide by the force of the single opposingclamping surface and can be firmly gripped between the clamping surfaceand the wall of the probe guide. In such an embodiment, the clampingsurface of the clamp need not be one side of an aperture defined by theclamp, but may be, by way of example, an outer edge of a clamp section,with no opposing piece on the clamp.

A clamp can be formed of any biocompatible, sterilizable material. Forinstance, in one embodiment, at least that portion of a clamp thatdefines a clamping surface can be formed of a material that is harderthan a probe to be held by the clamp, for example a hard polymer or astainless steel. In this embodiment, the clamping surface(s) can cutinto the surface of a probe, providing additional holding power inaddition to the friction hold provided by trapping the clamp with theclamping surface(s). In another embodiment, however, a clamp, andparticularly a clamping surface of a clamp, can be formed of a materialthat is softer than a probe held in the clamp. For example, a clamp canbe formed of a relatively soft polymer such as soft polyurethane orother biocompatible polymeric material. In this embodiment, the clampingsurface(s) can deform somewhat as a probe is forced against the clampingsurface. The deformation of a clamping surface about a probe canincrease the force on the probe, more securely holding the probe inplace in the clamp.

A clamp can define additional features that can improve its holdingability. For instance, a clamping surface can define a series ofserrations. Upon contact between a probe and the clamping surface, theserrations of the edges can provide increased surface area for contactbetween the clamp and the probe, improving hold between the two.Moreover, in those embodiments in which the material forming theclamping surface is harder than that of the probe, serrations on thesurface of the clamping surface can cut into the surface of the probe atthe points of contact, further improving hold between the two.

Referring again to FIGS. 7A and 7B, clamp 156 includes formations 162,163 that can be used to move clamp 156 and trap probe 154 in theaperture 158 as previously discussed. For example, as illustrated inFIG. 8, a sterilized shield 130 can be held against the skin surface ofa subject and the user can move the clamp 156 with his/her thumb toforce the probe into the narrow section of aperture 158 and firmly clampthe probe 154 in place.

In the illustrated embodiment, clamp 156 includes two formations 162,163, one on either side of clamp 156 such that the clamp can be operatedwhile held in either the right or left hand of a user. In otherembodiments, clamp 156 can include only a single formation, for instancein those embodiments in which a probe device is designed for onlyright-handed or left-handed use, or alternatively, when the singleformation can be accessed from either side of the device. Moreover, theshape of the formations 162, 163 can be any shape that can be accessedby a user and can be pushed, pulled, twisted or otherwise activated tomove a clamp and tightly grip a probe in a probe guide. For example aformation can be round, as illustrated, or can be a flat, paddle-shapedformation, a post, or any other convenient shape. Moreover, anyformation can be utilized to aid in moving the clamp to force a clampingsurface against a probe. For instance, a clamp can define an indentationto be used in moving a clamp. In another embodiment, a clamp can definea rough tactility at a location that can aid in moving the clamp with athumb or finger. Equivalent or alternative formations would be obviousto one of ordinary skill in the art. For instance, in anotherembodiment, a portion of the clamp can be rotated so as to force theclamping surface of the clamp against a probe held in the probe guide.By way of example, a probe clamp as is illustrated in U.S. Pat. No.7,244,234 to Ridley, et al., previously incorporated by reference, canbe utilized in conjunction with disclosed devices.

Referring again to FIG. 3, clamp 156 is attached to shield 130 at apivot point. For instance, tabs 164 of clamp 156 can fit into recesses165 formed in the lower section 132 of sterilizable shield 130 (see,e.g., FIG. 5A). During use, clamp 156 can rotate about the pivot pointof tabs 164 and over the rounded upper surface of portion 160 of uppersection 134 such that the clamping portion, i.e., that portion of clamp156 that defines the aperture 158 crosses the axis of the probe 154 tolock the probe in place.

The rotation of a clamp about a pivot to secure a probe is not arequirement of disclosed clamps. For example, in another embodiment, theentire clamp can slide laterally across a portion of a probe device,e.g., a shield or a transducer housing, to clamp a probe in place. Ingeneral, any motion of all or a portion of a clamp that can becontrolled by a user and can grip a probe as described is encompassed inthe present disclosure.

When a probe is to be removed from a percutaneous location, or if duringa procedure, a probe is to be moved from one percutaneous location toanother, a projection can be moved in the opposite direction as was usedto clamp the probe, freeing the probe.

FIG. 9 illustrates another embodiment of an ultrasound transducerhousing 800 that can be removably attached to a sterilizable shield.According to this embodiment, ultrasound transducer housing 800 caninclude a handle 802, a post 804, and a base 806. Ultrasound transducerhousing 800 also defines a lower surface 810, as shown. In thisparticular embodiment, however, the ultrasound transducer housing doesnot include a probe guide opening. Instead, ultrasound transducerhousing 800 is removably attachable to a second portion of a device thatdefines a probe guide opening. For instance, ultrasound transducerhousing 800 can be utilized in conjunction with a sterilizable shieldthat defines the probe guide. Moreover, the sterilizable shield can beformed of single or multiple removably attachable pieces.

FIGS. 10A and 10B illustrate one embodiment of a sterilizable shield 930that can be used in conjunction with an ultrasound device 800illustrated in FIG. 8. With reference to FIG. 10A, sterilizable shield930 can be formed of multiple attachable pieces. Specifically,sterilizable shield 930 includes section 932 and section 961 thatdefines a probe guide for passage of a probe therethrough. Accordingly,section 961 can alternatively be referred to as a probe guide portion.Additionally, section 932 can be separable into two or more sections, asillustrated for device 230 of FIGS. 3-6. Section 961 can also includeclamp 956 defining aperture 958 and formations 962, 963 that rotatesabout pivot 964 for clamping probe 954 in the probe guide. During use,section 961 can be attached to shield 932, for instance by use ofaligned tabs and notches, and so forth, so as to attach the probe guideportion to the sterilizable shield, as shown in FIG. 10B.

Of course, any other arrangements of the individual portions of a deviceare encompassed within the present disclosure. For instance, in oneembodiment, an ultrasound transducer housing that does not define aprobe guide opening, as illustrated in FIG. 9, can be removably attachedto a probe guide portion that can define a probe guide opening andinclude the clamp, without enclosing all or a portion of the ultrasoundtransducer housing in a shield. In another embodiment, a sterilizableshield portion can cover only the skin contacting surface of a device.For instance, a shield portion can snap onto the base of a device. Inyet another embodiment, all or a portion of a sterilizable shield can beformed of a pliant material that can enclose an ultrasound transducerhousing. According to such an embodiment, a probe guide portion can beindirectly attached to the pliant sterilizable shield portion, forinstance by use of a frame or other attachment device that is on thepliant material or optionally on the ultrasound transducer housingitself, such that the pliant material of the shield is held between theframe and the probe guide portion.

Yet another embodiment is illustrated in FIG. 11. As can be seenaccording to this embodiment, a device 1000 need not include a separatehandle portion. Such a device can be comfortably held by the roundedback portion 1002, while holding the angled skin contacting surface 1110against a subject. A side view of device 1000 shown in FIG. 12 betterillustrates the angle of skin contacting surface 1110. Of course, asdiscussed above, a device need not include an angle in the skincontacting surface, and in another embodiment the skin contactingsurface of a device can be flat with no angle as is shown for the deviceof FIG. 11, or arcuate.

A front view of device 1000 is shown in FIG. 13. As can be seen, device1000 includes attachment slots 1004, 1006 on either side of the device.These attachment slots 1004, 1006 can be utilized to attach anotherportion to device 1000. For example, FIG. 14 illustrates device 1000including a probe guide portion 1061 attached to device 1000 via slots1004, 1006. When attached, probe guide portion 1061 can, in oneembodiment, be attached such that probe guide 1039 is aligned with anultrasound transducer located in the base of device 1000. Of course,device 1000 need not include an ultrasound transducer in the base. FIG.15 illustrates a side view of device 1000 including probe guide portion1061 attached thereto. As can be seen, probe guide portion 1061 candefine skin contacting surface 1008 and device 1000 can device skincontacting surface 1010, with the two surfaces 1008, 1010 held at anangle to one another to promote improved contact between a device and asubject, as previously discussed. FIG. 16 is a front view of theembodiment illustrated in FIGS. 14 and 15.

In one embodiment, all or a portion of device 1000 can be covered orencased with a sterilizable shield. For instance all of the body 1000 ofthe device can be encased in a sterilizable shield, and the probe guideportion 1061 can then be attached to the sterilizable shield.Alternatively, one a portion of the device, for instance the skincontacting portion, can be covered by a sterilizable shield. In oneembodiment, the probe guide portion 1061 can be sterile, and the portion1000 can be nonsterile.

In one embodiment, a probe guide portion need not include a skincontacting surface. For instance, a separably removable probe guideportion can be attached to a device such that the base of the probeguide portion will be above and not contacting the skin of a subject.According to this embodiment, contact between a subject and a devicewill only be between the body of a device that encompasses theultrasound transducer, For instance, when the body of a deviceincorporates an ultrasound transducer therein, the skin contactingsurface can be at the surface from which an ultrasonic beam is emitted,and the probe guide portion can be aligned with the transducer, but heldabove the skin contacting surface of the body of the device. In thisembodiment, a probe passing through a probe guide will exit the probeguide and pass for a distance through the surrounding air prior tocontacting the skin of a subject and passing therethrough.

Additionally, though illustrated in FIG. 14 with probe guide portion1061 completely defining and surrounding the probe guide 1039 thatpasses therethrough, this is not a requirement of the presentdisclosure. For example, in another embodiment, a probe guide can bedefined between a probe guide portion 1061 and the side of device 1000.According to this embodiment, a probe guide portion can define aV-shaped notch, a slot, a semi-circular cut out or the like in the sideof the probe guide portion that will contact the device 1000. Uponattachment of the probe guide portion to the body of the device, theprobe guide can be completely formed. Moreover, the side of the body ofthe device can also define a portion of a probe guide, in oneembodiment, and the probe guide can be formed between the two removablyattachable portions of the device.

A probe guide portion can also be formed of multiple removablyattachable pieces, if desired.

FIG. 17 illustrates the device 1000 following attachment of a clamp 1056to the probe guide portion 1061. FIG. 17 illustrates this embodiment ina side view and FIG. 18 illustrates this embodiment in a front view.During use, a device can be held against the skin and a probe can bepassed through the probe guide. Upon reaching the desired subdermallocation, the clamp 1056 can be activated, for instance by the userpulling formation 1063 from the unclamped to the clamped position.

Utilizing presently disclosed devices, a probe tip can be guided to apercutaneous target on a line that is parallel to the plane imaged on asonogram formed by use of an ultrasound transducer incorporated in adevice. For instance, the probe tip can travel on a path that defines aline that is coincident in the scanned plane, is parallel to the scannedplane, or intersects the scanned plane at a point. When utilizing thepresently disclosed devices, the path of the probe to the target can beknown, even if it cannot be discerned on the sonogram: the probe willadvance toward the target on a straight line and at a predeterminedangular relationship to the ultrasound housing base from the probe guideopening to the target that is imaged by the ultrasound. Thus, the pathof the probe and the scanned plane of the sonogram image can both bedefined by the orientation of the transducer and can be coordinated onthe target. In order to strike the target, the probe can be merelyguided along this known path the desired distance.

In an ideal situation, the probe itself can be visualized on the scannedplane. For instance, in those embodiments in which the path of the probeis on a line within the scanned plane, the probe can be seen in thesonogram, depending on the density of surrounding tissue and otherprocess parameters. However, in one embodiment, even if the path of theprobe is coincident with the scanned plane, the probe itself may not bevisible on the sonogram, but artifacts of the passage of the probe canbe visualized, e.g., shadows, motions of internal structures as theprobe passes, and so forth.

In one preferred embodiment, the known path of the probe can be added tothe sonogram, and the targeting procedures can be even furthersimplified. For example, one embodiment includes the addition of atargeting line on the sonogram extending from that point on the sonogramwhere the probe guide opening exits the housing (or passes thetransducer) and projecting across the ultrasonic field in a straightline at the known angle. Thus, if this targeting line is made tointersect the target that is imaged by the device, the operator can beconfident that the probe is accurately directed to the target. In otherembodiments, other targeting information can be displayed on thesonogram. For example, in one embodiment, information showing theapproach of the probe to the target can be displayed.

In one particular embodiment, a motion detector can register motion of aprobe in the probe guide, and that information can be displayed, forinstance, as a real time image of the probe on a screen or monitor. Inthis embodiment, the location of the probe tip in relation to the targetand the moment when the probe tip strikes the target can be seen in realtime by an operator watching the virtual probe on the monitor during theprocedure.

FIG. 8 illustrates one embodiment of the presently disclosed subjectmatter during use in which an image of a virtual probe may be overlaidon a sonogram. In this particular embodiment, the probe device caninclude a detector 170 located in the post of the sterilizable shield orin the post of the transducer housing. Detector 170 can recognize andmonitor the movement of probe 154 as it passes through probe guide andinto a subject. Information from detector 170 and the ultrasoundtransducer can pass through cable 124 to monitor 174. The probe 154 canthen be imaged on a monitor 174 as probe image 178. The monitor 174 canalso show the internal target, for instance a blood vessel 176.

A variety of different possible detectors as are generally known in theart may be utilized as detector 170. For instance, detector 170 canutilize infrared (IR), ultrasound, optical, laser, magnetic or othermotion detection mechanisms. In addition, the location of detector 170is not critical to the invention. In the embodiment illustrated in FIG.8, detector 170 is located in the post of either the shield 130 or theultrasound transducer housing enclosed within the shield 130. In otherembodiments, however, the detector may be located elsewhere in thesystem including, for example, on a portion of the probe itself.

Signals from detector 170 can create a data stream which can be sent toa processor. A processing unit can be internal or external to thehand-held device. For example, data from detector 170 can be sent to astandard lap top or desk top computer processor or part of aself-contained ultrasound system as is known in the art. A processor canbe loaded with suitable recognition and analysis software and canreceive and analyze the stream of data from detector 170. The processingunit can also include standard imaging software as is generally known inthe art to receive data from the ultrasound transducer via cable 124.Probe 154 can be of a predetermined length which can be input dataentered into a processor by the user or can be preprogrammed into thesystem as default data. Thus, through analysis of the data streamreceived from detector 170 and from ultrasound transducer 120, aprocessor can be programmed to calculate the relative position of theprobe tip in relation to the ultrasound transducer 120, in relation todetector 170, in relation to the exit of the probe guide, or to anyother convenient reference point. A processor can communicate thisposition information digitally to monitor 174 and the information can bedisplayed on the monitor such as in a numerical format or optionally asa real time image of a virtual probe 178 shown in conjunction with thesonogram including an image 176 of the target, such as a blood vessel.

In such a manner, disclosed devices can be utilized to actually show theapproach of the probe toward the target on the monitor throughout theentire procedure. In addition, in certain embodiments, disclosed devicescan be utilized to ensure the probe tip remains at the target duringsubsequent procedures. For example, in those embodiments wherein thedetector 170 monitors the motion of the probe 154, as long as probe 154remains ‘visible’ to detector 170, the image 176 of probe 154 can remainon the monitor 174. Thus, any motion of the probe tip in relation to thetarget can be noted by an observer.

The presently disclosed ultrasound guided probe devices and methods maybe utilized in many different medical procedures. Exemplary applicationsfor the devices can include, without limitation

-   -   Central Venous Catheterization    -   Cardiac Catheterization (Central Arterial Access)    -   Dialysis Catheter Placement    -   Breast Biopsies    -   Paracentesis    -   Pericardiocentesis    -   Thoracentesis    -   Arthrocentesis    -   Lumbar Puncture    -   Epidural Catheter Placement    -   Peripherally Inserted Central Catheter (PICC) line placement    -   Thyroid Nodule Biopsies    -   Cholecystic Drain Placement    -   Amniocentesis    -   Regional Anesthesia—Nerve Block

Some of these exemplary procedures have employed the use of ultrasoundin the past, and all of these procedures, as well as others notspecifically listed, could utilize the disclosed ultrasound guideddevices to improve procedural safety as well as patient safety andcomfort, in addition to provide more economical use of ultrasounddevices. In addition, the presently disclosed devices may be utilizedwith standard probe kits already available on the market.

It will be appreciated that the foregoing examples, given for purposesof illustration, are not to be construed as limiting the scope of thisinvention. Although only a few exemplary embodiments of this inventionhave been described in detail above, those skilled in the art willreadily appreciate that many modifications are possible in the exemplaryembodiments without materially departing from the novel teachings andadvantages of this invention. Accordingly, all such modifications areintended to be included within the scope of this invention which isdefined in the following claims and all equivalents thereto. Further, itis recognized that many embodiments may be conceived that do not achieveall of the advantages of some embodiments, yet the absence of aparticular advantage shall not be construed to necessarily mean thatsuch an embodiment is outside the scope of the present invention.

What is claimed is:
 1. A medical probe device comprising a first portioncomprising an ultrasound transducer housing; a second portion, thesecond portion defining at least a portion of a probe guide for passageof a probe therethrough, the probe guide providing an unimpededpassageway through the medical probe device, the second portion beingremovably attachable to the first portion; a detector for detectingmotion of a probe within the probe guide, the detector being incommunication with a processor for displaying information concerning themotion or position of the probe within the probe guide.
 2. The medicalprobe device of claim 1, further comprising a sterilizable shield forencasing at least a portion of the device.
 3. The medical probe deviceof claim 2, the first portion defining a first surface, the ultrasoundtransducer being located in the first portion such that an ultrasonicbeam issued from the ultrasound transducer is emitted from the firstsurface, wherein the sterilizable shield encases the first surface ofthe first portion and remaining surfaces of the first portion are notencased by the sterilizable shield.
 4. The medical probe device of claim2, wherein the sterilizable shield encases the entire first portion, thesecond portion being directly or indirectly removably attachable to thesterilizable shield.
 5. The medical probe device of claim 1, the firstportion defining a skin contacting surface, wherein the second portiondoes not contact the skin of a subject when the skin contacting surfaceof the first portion is in contact with the subject's skin.
 6. Themedical probe device of claim 1, wherein the information is displayed asan image of a virtual probe on a monitor in communication with theprocessor.
 7. The medical probe device of claim 1, wherein the sensor isintegral to the first portion.
 8. The medical probe device of claim 1,wherein a portion of the probe guide is defined by the first portion anda portion of the probe guide is defined by the second portion.
 9. Themedical probe device of claim 1, wherein the entire probe guide isdefined by the second portion.
 10. The medical probe device of claim 1,wherein the second portion is sterile.
 11. The medical probe device ofclaim 1, wherein the second portion comprises multiple removablyattachable pieces.
 12. The medical probe device of claim 11, wherein oneof the removably attachable pieces is a clamp.
 13. A method for guidinga probe to a percutaneous target comprising attaching a first portion ofa medical probe device to a second portion of the medical probe device,the first portion comprising an ultrasound transducer housing and thesecond portion defining at least a portion of a probe guide for passageof a probe therethrough, the probe guide providing an unimpededpassageway through the medical probe device, the second portion beingremovably attachable to the first portion; passing a probe through theprobe guide to a percutaneous target; detecting motion of the probewithin the probe guide, the detector being in communication with aprocessor; and displaying information concerning the motion or positionof the probe within the probe guide.
 14. The method of claim 13, furthercomprising encasing at least a portion of the device with a sterilizableshield.
 15. The method of claim 13, wherein the second portion does notcontact the skin of a subject during use and the probe exits the probeguide at a distance from the skin of the subject.
 16. The method ofclaim 13, further comprising forming an image of a virtual probe on amonitor in communication with the processor.
 17. The method of claim 13,wherein the complete probe guide is formed only upon attachment of thefirst portion to the second portion.
 18. The method of claim 13, whereinthe second portion is sterile.
 19. The method of claim 13, furthercomprising combining multiple removably attachable pieces to form thesecond portion.
 20. The method of claim 13, further comprising clampingthe probe in the probe guide when the probe guide is at the percutaneoustarget.